Boat cap



FIG. 1 is a bottom plan view of a boat cap showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof; and,

FIG. 5 is a side elevational view thereof, the opposite side view being a mirror image of that shown.

The broken lines shown in FIGS. 3 through 5 are for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a boat cap, as shown and described. 